Simple linear motor design ?

I need a simple, not powerfull, linear engine. It has to move just like an inch back and forth, chaning directions on its own when it reached the end of his stroke. Even 5mm would be enough movement. I think about of something based on a neodymium magnet in cylinder shape. It has to be as simple as possible, i don't need any control for frequenzi, because if it works.. i can work out more from there on my own. Only thing important, it has to be small, like the lenght of a half pencil and 2cm in diameter would be ok (for the moving part, electronics placed elsewhere don't matter). A normal rotating engine with a shaft doesn't work for the design i have in mind :(

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benthekahn8 years ago
Have a motor turn with a bolt on the shaft. If the bolt is prevented from turning, it will move in a linear motion.
wupme (author)  benthekahn8 years ago
I never heared of that, but it actually works, thats great. Finding a small enough motor shouldn't be a problem now :)
S1L3N7 SWAT8 years ago
If you're not opposed to buying one they have some here:


Scroll down a bit and you'll see some small linear actuators, they're called "Miga".
frollard8 years ago
a hard drive armature is technically an axial design like you dont want, but might be able to be modified - and its extremely accurate. You basically just need a magnet inside a tubular coil. A mechanical switch could be used to reverse the current when it gets to either end of the stroke.
wupme (author)  frollard8 years ago
Thats actually a great idea, i didn't think of that. I'm sure i got a couple of old harddrives that don't work anymore somewhere here. Geez, i moved in over a year ago, and still half of my stuff is in boxes.